Behind a chain link fence, Paul Jacob watches water spill over a dam on Neville Island—a 1,200-acre stretch of land in the Ohio River near Pittsburgh that’s a hive of industrial lots and chemical plants.
But to Jacob, the white froth at the base of the Emsworth Back Channel dam—built in 1936—represents an opportunity.
“The water over that dam—that basically is unused energy,” Jacob says. “You’ve got a substantial flow of water.”
Jacob is the chief commercial officer for Rye Development, a Boston-based company proposing to build a hydropower plant at Emsworth and nine other dams in western Pennsylvania and West Virginia. If approved, the projects could come online as early as 2019.
They are part of what some are hoping is a renaissance for hydropower—the oldest renewable energy resource. Only three percent of the nation’s 80,000 dams have hydropower installations on them, and some developers, like Rye, are hoping to piggyback their turbines on this pre-existing infrastructure.
Emsworth is part of the Army Corps of Engineers’ extensive system of locks and dams along the Ohio and Mississippi river systems. This decades-old system is designed for flood control, navigation and to maintain water quality. But Jacob also sees a wealth of untapped power. The powerhouses Rye Development is proposing to build on the dams would direct some of the river flow into underwater turbines—basically, a 12-foot propeller—and generate electricity from it.
Jacob says there’s not much to it.
“The type of turbine we’d be using was first designed in 1909, and it hasn’t changed much since,” he says. “People have been using hydro for 10,000 years or so, so there’s not a lot of mystery to it.”
At 12 megawatts, the Emsworth dam is a modest-sized project. It could power only 6,000 to 12,000 homes. That’s a tiny fraction compared to the million or so homes a big coal-fired power plant or a major hydro plant— like the Hoover Dam or Niagara Falls—can light up. But the combined output of all of the company’s projects in the region would add up to 200 megawatts—enough to power up to 200,000 homes.
“It’s a carbon-free resource, and once it’s built, it’ll just operate,” Jacob says. “The life of these projects is extremely long compared to most other resources. So it makes a good contribution—adding a renewable resource that’s also available on a 24-7 basis.”
By comparison, wind and solar are more intermittent renewable energy sources: When the wind isn’t blowing or the sun isn’t shining, they can’t produce electricity. So adding reliable sources of power that generate electricity at all hours is a big push for people trying to get more renewables onto the grid. Advocates for hydropower say their resource could fit the bill.
Fast-growing wind and solar may garner a lot of attention. But hydropower is still the biggest source of renewable energy in the country—accounting for 50 percent of all renewable energy and 7 percent of all electricity in the U.S.
“It’s talked about as the ‘silent renewable,’” says David Zayas, senior manager for regulatory affairs and technical services at the National Hydropower Association.
Zayas says hydropower has been around so long, some people assume there’s no room for it to grow. But the U.S. Department of Energy says the industry could grow by 50 percent over the next three decades.
“The myth is that hydropower is all tapped out. I think Pennsylvania is a really good example of that not being the case.”
In fact, Zayas says with its plentiful rainfall and dammed rivers, Pennsylvania ranks sixth in the country in potential for growth in hydro.
A potential renaissance in hydropower construction could be impacted by the election of Donald J. Trump. Trump has vowed to do away with President Obama’s Clean Power Plan, which gave states incentives to construct hydropower plants.
Jacob says he doesn’t know yet how a Trump presidency will impact the industry, but he doesn’t think it will hurt his company’s own business plan. He says the alternative energy targets set by states and individual companies, like Google, are helping get more clean energy on the grid.
“One of the biggest drivers, nationally, is on the corporate side,” Jacob says. “Corporations are focusing on having renewable portfolios of their own. We’re seeing that interest from a broad swath of companies, and that’s not driven by any regulatory moves from the federal government.”
Environmental groups have often frowned on hydropower because big, new dams can wipe out habitat and displace homes and businesses. But some environmental groups are latching onto the idea of building them on pre-existing dams like Emsworth. Lindsay Baxter of the Pennsylvania Environmental Council says in those cases, we might as well take advantage of dams where habitats have already been altered.
“Where you have a previously disturbed environment, sometimes those can be retrofitted to produce power with very little or no impacts on the environment,” she says.
But some worry that new hydropower plants—even on existing dams—could be bad for rivers.
State and federal wildlife agencies worry they can deprive fish and wildlife of dissolved oxygen.
“All aquatic life, even though they live in water, they need air to breathe,” says Rose Reilly, a biologist with the Army Corps of Engineers’ Pittsburgh District.
Dams act like aerators in aquariums, infusing Pittsburgh’s Three Rivers with oxygen. A hydropower plant funnels some of this water into turbines, instead of letting it tumble over the dam. This could drop the rivers’ oxygen levels, which already run low during summer.
“If you put in the hydropower turbine, there’s little or no aeration, so you lose the benefits provided by the dams,” Reilly says.
Rye Development will need to negotiate with the Corps of Engineers over how much river flow—and dissolved oxygen—it can divert for its projects. But oxygen isn’t the only thing hydropower plants could impact.
Since fish thrive on the oxygen-rich waters near dams, the vast majority of fishing in the region happens close to dams. Putting powerhouses onto dams could subtract from the already limited access that anglers have to the rivers, according to Rick Lorson, area fisheries manager for the Pennsylvania Fish and Boat Commission.
“A lot of these rivers, being in industrial-type areas, do not have a lot of access to the riverbanks,” Lorson says. “So we have to be very careful and concerned about losing any of that.”
That limited access was on display on a recent afternoon near the Highland Park Dam on the Allegheny River in Pittsburgh, a few miles from where the river flows into the Ohio. It’s another Corps of Engineers dam Rye Development is eyeing as a site for a future hydropower plant.
Rob Walters, executive director of Three Rivers Waterkeeper, steers a motorboat close to the dam, on an unseasonably warm fall afternoon. Walters’ group monitors water quality on Pittsburgh’s rivers, which have slowly seen fish populations rebound after decades of industrial pollution.
At the side of the dam, Walters spots a man on a spit of rocks, just below where the powerhouse on Rye’s Highland Park dam project would be built. The man sits in a chair he’s brought down to the shore. Next to him: a cooler, a bait bucket and a fishing rod. Walters says, from the looks of it, the man is after catfish.
“There are some huge flathead catfish up here,” Walters says, with more than a little envy. “That guy’s probably having the time of his life.”
Walters doesn’t know what the final plan at Highland Park will look like, but he’s worried this catfish spot could get wiped out by the hydropower plant. He’s in favor of clean energy, but he doesn’t want it to come at the cost of the region’s still-recovering rivers—and those who use them.
“To the gentleman that’s up there, this is his Yosemite,” he says. “Why should we take that away from him?”